Rare 3 cylinder CAT RD6/D6

Rare 3 cylinder RD6 / D6 at the National Pike show, Brownsville PA.

The early RD6 / D6 was part of a family including the RD7 + RD8, with common bore + stroke, hence an opportunity for some parts commonality. The RD8 had 6 cylinders, the RD7 had 4 cylinders, and the RD6 had 3 cylinders.

About 1941, CAT redesigned the D6 to share B+S with the D4, the D6 then had 6 cylinders, and the D4 had 4.

This machine was apparently intended to be an Ag tractor, and is geared too fast for blade work. The 3 cylinder engine has a nice bark to it...

At the end, compare its size with the newer D4.

Category:

Autos & Vehicles

Tags:

• Caterpillar
• CAT
• dozer
• bulldozer
• RD6
• D6
• National
• Pike
• Brownsville
• HCEA

[SteamCrane]

I don't have the parts book on it, but the RD6 apparently has a lot of parts commonality with other Cats of the same timeframe. Engine is essentially 3/4 of a D7, and 1/2 of a D8 of the era. A guy I know that had a 60 said that a lot of tranny parts interchange with older D6's.

There were 2 versions of RD6, identifiably by long or short injector body, older is the long body.

You know what it sounds like, I'd go for it!

[tubulli]

I wonder why he´s running it in such a high gear.

1. would be appropriate

[SteamCrane]

Owner says it was built as an ag tractor, with higher gearing for plowing and disking. Not suited for blade work, but fun anyway.

[MrStonemike]

Raised by a true blue "dirt hand "from the forties, I can tell you a good operator never runs in first gear, you can push a full load usually in second, cleaning up a pipeline burm, my Dad sometimes would run in third!

[rotundrooster]

That's a high speed skidder,not a ag cat.

I've never seen one with that fast of a low gear,can't be anything else,couldn't pull 5 bottom plow with that.

[stehansen0051]

There weren't many of those wide guage models used around here. I have a narrow gauge model and it has been sitting for 2 years. It has a problem with the carburator. Just won't get gas into the pony motor. Almost every farm on the west side of the central valley had at least one of these. 

[TheGarrettDressler]

PUH! who needs AC in their cab.

[1bad55chev]

What more do you know about the rd6, I found one destined for the scrap-man and really want to rescue it. Its a 3 cyl logger w/ a winch an hydraulic blade.

[JAROSLAVAGINA]

that thing talks dirty! beautiful! lovely rhythm.

[Rinty145]

I bet it's very economical?